I'm not aware of any such issue... there are a couple of explanations, and all of them are basically user error.
By the way, if you want a faster response, you should check out the discord
I've been working on a wiki for v10. You can find it here:
https://smrpga.fandom.com/wiki/Super_Mario_RPG:_Armageddon_Wiki
You can also come visit us on the SMRPGA discord here:
https://discord.gg/8ENqJEE3Fa
Come visit us, and we'll help in whatever way we can!
If you defeated the Axem Rangers, you should trigger a cutscene when you enter the large room in the back of the palace. After that cutscene, the royal bus will be working.
https://www.speedrun.com/smrpg_armageddon
There currently aren't any speedruns for v9. They would need to be a single segment, with video for the entire run.